The present invention relates to a motor-driven wrench.
More particularly, it relates to such a wrench which has an open wrench wheel with a friction surface or toothing.
In such known wrenches the open wrench wheels are rotated by means of a plunger or ratchet. The rotation is performed either only in one direction or, after switching a bar, can be changed. For changing the rotary direction the wrench must be either turned by 180.degree. or changed over with a bar. Both approaches increase the cycle time in automatic manufacturing processes.